A subspace field pulse was a process used in Geordi La Forge's VISOR.

In 2370, Lieutenant Worf was thrown into a state of quantum flux as a result of an encounter with a quantum fissure, causing him to enter a different quantum reality. The quantum flux in Worf's cellular RNA was intensified by the field pulse in Geordi's VISOR whenever he came close to Geordi, causing him to shift to a different quantum universe each time. (TNG: "Parallels")